Internal pipe cutter



Sept. 4, 1962 J. F. COURTNEY INTERNAL PIPE CUTTER 5 Sheets-Sheet 1 Filed Oct. 31, 1960 Sept. 4, 1962 J. F. COURTNEY INTERNAL PIPE CUTTER 5 Sheets-Sheet 2 Filed 001:. 51, 1960 INVENTOR.

Sept. 4, 1962 J. F. COURTNEY INTERNAL PIPE CUTTER 5 Sheets-Sheet 3 Filed 001;. 31, 1960 INVENTOR. ayazngoj KMMJ Sept.-4, 1962 J. F. COURTNEY 3,052,024

INTERNAL PIPE CUTTER Filed Oct. 31, 1960 5 Sheets-Sheet 4 I l l l I l l INVENTOR.

wzam Sept. 4, 1962 J. F. COURTNEY INTERNAL PIPE CUTTER 5 Sheets-Sheet 5 Filed Oct. 31, 1960 INVENTOR. a 9 W United States Patent 3,052,024 INTERNAL PIPE CUTTER Joseph F. Courtney, New Orleans, La., assignor of fifty This invention relates to a new and improved internal pipe cutter.

With the advent of the off shore oil drilling, problems in related fields have arisen. For example ,when a well site in the ocean is to be abandoned it is desirable from a navigational standpoint to entirely remove all of the well rigging. Quite often the rigging or structure includes a plurality of concentric pipes, some of which have cementitious fillings therebetween. The removal of such rigging has up to the present time required blasting with explosives. This blasting practice is extremely ditficult and costly. Attempts by others have been made to produce pipe cutters, but when it is considered that all of the cutting equipment must pass down the innermost pipe in a column of concentric pipes, it is not difiicult to understand their failures. One pipe at the most could be cut from inside out with existing equipment.

It is therefore a principal object of this invention to provide a pipe cutter capable of cutting through a plurality of concentric pipes from inside out.

An important object of this invention is the provision of means for fixedly positioning an internal pipe cutter at any desired location within a pipe to be cut and remotely controlling the rotation of the cutter and the radial extension of a cutter element through the walls of pipe to be cut.

Another important object of this invention is to supply an internal pipe cutter with a transversely disposed cutting element of a length substantially the same as the internal diameter of the pipe in which the cutter is inserted, and means for gradually extending said transversely disposed cutting elements substantially its full length.

A still further important object of this invention is to equip an internal pipe cutter with a cutting element capable of cutting a plurality of superposed concentric pipes up to approximately two and one-half times the internal diameter of the innermost of said concentric pipes and within which the internal cutter is inserted.

Another and still further important object of this invention is to provide a means for cutting off pipe rigging in abandoned 0E shore oil wells beneath the surface of the water at any desired level without destroying marine life and without the necessity of sending divers down from the outside to cut through the pipe structure from the outside.

Still another important object of this invention is the provision of means in an internal pipe cutter for making a smooth cut on the pipe or pipes being cut to permit easy plugging or capping thereof for subsequent reuse of the remaining pipes.

Other and further important objects and advantages of this invention will become apparent from the disclosures in the following specification and accompanying drawings.

In the drawings:

FIGURE 1 is a vertical sectional view taken through a pipe assembly and having the pipe cutter of this invention FIGURE 5 is a sectional view taken on the line 5-5 of FIGURE 1.

FIGURE 6 is a sectional view taken on the line 6-6 of FIGURE 1.

FIGURE 7 is an electrical wiring diagram of the indicating means to remotely show the cutting tool extension.

FIGURE 8 is a side elevational detail, partially in section, of the jaw clamping mechanism.

As shown in the drawings:

The reference numeral 10 indicates generally a pipe which is the inner of several concentric pipes. An intermediate pipe 11 and an outer pipe 12 complete this series of concentric or superposed pipes shown in the drawing. Cement 13 fills the annular space between the inner pipe 10 and the intermediate pipe 11. Similarly cement 14 fills the annular space between the intermediate pipe 11 and the outer pipe 12. This assembly of pipe and cement is one which occurs quite frequently in the industry that is commonly referred to as off shore oil well drilling. When oil wells are drilled in the ocean floor pipes and pipe assemblies as shown in this drawing are placed therein with a considerable degree of permanence. When the oil in a particular pocket is depleted to the point where it is impractical to continue operation of the well, it is abandoned. The problem then arises as to how or whether to remove the permanent pipe assemblies. If they are left in the water they become a serious hazard to navigation. Most contracts as now Written whether with the individual States or the Federal Government condition the grant upon the provision that all pipes, pipe assemblies, and any structures above ocean floor level be removed.

The method of pipe removal has taken several forms. One such method is to dynamite the structure, but this is costly, requires examination by divers after completion, and is detrimental to ocean life. Another such method is to send down divers to cut off the pipe and pipe assemblies. This last procedure is both costly and hazardous to the well being of the divers employed. The present invention contemplates the cutting of these pipes and pipe assemblies from inside out by lowering cutting equipment down inside the pipe from the top. This is economical as well as relatively safe and efiicient.

A pipe cutting head 15 is generally of cylindrical shape and of a 'size capable of sliding vertically within the inner pipe 11. A cutting tool 16 is arranged and constructed in the head 15 in such a manner that it may be propelled generally radially outwardly, as will later be described, for the purpose of cutting through the entire pipe assembly as the cutting head 15 rotates.

The pipe cutting head 15 is adapted to be lowered into the pipe by suitable means which will hereafter be described. However, the cutting head necessarily includes various other elements such as a gear reducer 17 disposed immediately above the pipe cutting head and having a bell shaped housing 18 disposed between the reducer 17 and the cutting head 15. A radial jaw for holding the assembly within the pipe at any desired setting is shown at 19. 'A housing 19a carries the jaw 19 which is arranged and constructed for radial extension. A similar jaw 20 is Vertically spaced apart from the jaw 19 and it is mounted in a housing 20a which is disposed above the housing 19a. The housing 19a is carried on the bell housing 18 by several spaced apart radial ribs 18a. Both of these housings 19a and 20a form part of the stationary housing of the gear reducer and/or the other mechanisms to be subsequently described. A rod member 21 extends between and is journaled within the housings 19a and 20a and upon longitudinal movement thereof operates to extend the radially movable jaws 19 and 20 as will subsequently be described and shown in FIGURE 8.

A motor 22 is employed to impart drive to the cutting head 15 and may be any type of motor, but the one particularly adapted to service of this type is an air motor. The housing 20a is supported on radial ribs 22a which are fixedly mounted on the motor 22. A cross head 23 is fastened to the top of the motor 22 and is used to carry the entire unitary assembly of motor, gear reducer and cutting head. A centrally disposed block 24 is weldably attached to the cross head 23 and is adapted to receive a downwardly depending link 25. A cotter pin 27 passes through the cross pin 26 at the end thereof to hold the pin engaged within the block and to thus hold the depending link engaged with the block. A circular link of a chain type as shown at 28 is weldably attached to the downwardly depending link 25. A cable 29 is looped through the circular link 28 and has windings 29a thereon to hold the loop in the lower end of the circular link 28.

Conduits 30 and 36a constitute air hoses to carry air under pressure to the air motor 22. Similarly if the motor were an electrical motor the conduits would be used to deliver electrical energy thereto. A junction box 31 is mounted on the motor 22 and is utilized to receive the input and exhaust of the air used to drive the motor.

As best shown in FIGURE it is evident the device is held within the inner pipe by three equally spaced apart jaws. The radially movable jaw 19 has already been discussed. The two other jaws 19b and 19c are merely supported in the housing 1% and remain radially fixed with respect thereto. In operation, when the movable jaw 19 is radially extended it causes the jaws 19b and 19c to be thrust against the wall of the pipe 10 and thereupon securely hold the entire device in a fixed position therein. FIGURE 6 shows a similar environment for the radially movable jaw 20. Here the housing 20a holds stationary jaws 20b and 200 at equally spaced apart positions therearound so that the jaws 20, 20b and 2410 are at 120 with respect to each other in the same manner as the jaws 19, 19b and 190 in the housing 1%.

As best shown in FIGURE 8 the vertically disposed rod 21 has a piston 32 aflixed to the top thereof. Conduits 33 and 33a are employed to deliver r remove air under pressure to and from a cylinder housing 34. Admission of air or other fluid under pressure through the conduit 33 to the upper portion of the cylinder 34 causes the piston 32 and rod 21 to be forced downwardly. Simultaneously the conduit 33a acts as an exhaust passage for the fluid within the bottom of the cylinder 34. Conversely, when the procedure is reversed and fluid is admitted through the conduit 33a and exhausted through the conduit 33 the rod 21 moves upwardly. Cam members 35 and 35a are alfixed to the rod 21 at spaced positions thereon and lie closely adjacent the radially movable jaws 19 and 20. Each such jaw is provided with a cooperative inclined face 35b and 35c which is engaged by the cams 35 and 35a respectively to cause an extension of the jaws when the rod 21 is forced downwardly by the fluid cylinder and piston 34-32. Conversely when the rod 21 is raised the jaws may retract into their housings 19a and 20a and permit withdrawal or relocationing of the entire pipe cutting device. There is no positive retraction of the jaws shown, but when the cams are moved away from the jaws there is nothing to hold them extended and they normally collapse inwardly.

The three jaws 19, 19b and 19c at evenly spaced intervals around the pipe 10 coupled with the three evenly spaced jaws 20, 20b and 200 at a vertically spaced apart location keep the stresses spread uniformly around the pipe. The spaced apart clamping means securely holds the cutting device in a fixed location during the cutting operation, and with only a single operator to effect locking or unlocking of both clamps simultaneously, the device is simple and effective.

Thus there is required for operation of this pipe cutting assembly four conduits. Two of these are used to supply the air operated motor and two are used to supply the jaw projecting motor for the extensible jaws 19' and 20. It should be understood that there could be a joint delivery of air pressure for the two means operable thereby, but for convenience the air under pressure is shown as being delivered separately to both the motor and the jaws.

An output or driven shaft 36 extends vertically downwardly from the motor 22 and gear or speed reducer 17 A worm 37 depends from the stationary part of the gear reducer housing and is disposed around the driven shaft 36. A worm gear 38 is in meshing engagement with the worm 37 and is supported within the pipe cut ting head 15. The worm gear is mounted on a shaft 39 which is journally supported in spaced bearing blocks 40 and 41 within the head 15.

A spur gear 4-2 is keyed to the shaft 39 and is in meshing engagement with a large spur gear 43. The large spur gear 43 is mounted on and afiixed to a threaded sleeve nut 44. An annular ring member 45 is weldably attached at 46 within the head 15 for the purpose of supporting certain of the elements as hereafter described. A plate member 47 is fastened to the annular ring 45 by means of cap screws or bolts 48. Thus the plate 47 is removably attached to the annular ring 45.

The plate 47 in turn carries spaced apart hanger bearings 49' and 50. The hanger bearing 49 is fastened to the plate 47 by means of cap screws or bolts 51 while the bearing is similarly attached to the plate by cap screws or bolts 52. The pipe cutting head 15 is provided with an internal boss 53. A spaced apart boss 54 also within the head 15 is in alignment with the boss 53 and together they are utilized to closely confine the threaded sleeve element or nut 44.

The threaded sleeve nut 44 is equipped with internal threads 55. The cutting head primarily consists of a flat rectangular blade portion 56 and a cylindrical, externally threaded integral end portion 57. It is this threaded end portion that is employed to threadedly engage the internal threads 55 of the sleeve nut 44 for the purpose of extending the cutting tool 16 radially from the head 15. An advancing cutting edge 58 i provided on the outer end of the cutting tool 16 and is hardened as required to cut through steel pipe and intermediately disposed cement or concrete fill.

A removable plate 59 forms a closure for the bottom of the head 15. Screws 60 hold the plate 59- in position on the head and thus enclose all of the gearing and essential lubricants therein.

An opening 61 in the plate 47 permits operating clearance for the worm gear 38. A cap 62 threadedly engages the lower end of the driven shaft 36. Cap screws 63- are arranged and constructed to hold a lock washer 64 to the bottom of the shaft 36 in adjacent relationship to the cap 62. The lock washer 64 has means to cause concurrent rotation of cap 6 2 and shaft 36. Another opening 66 is cut out of the plate 47 to permit meshing and rotation of the spur gears 42 and 43. A key 65 is used to form a driving connection between the shaft 36 and the plate 47. The operation of the device is such that the head 15 rotates all the time during cutting and the worm and spur gear mechanisms are used only to cause a gradual extension of the cutting tool 16. The driving shaft 36 is driven by the air motor 22. through the gear reducer 17. Thus the shaft 36 has its speed reduced from the speed of the motor and its torque increased. The joining of the shaft 35 to the plate 47 by the key 65 means that as the shaft 36 rotates so does the entire cutting head. If while the head rotates the cutting tool 16 is extended then anything around the head 15 will be cut into by the blade 16. The amount of extension must for efiective operation range from zero extension to full extension of the flat portion 56 of the tool 16.

The device is arranged to cause a gradual extension of the tool 16 while the head 15 rotates. This gradual extension of the tool 16 is caused by the worm gear 38 moving around the stationary worm 3'7 and being rotated thereby at an extremely slow rate of speed. As the worm gear 38 is rotated so also is the spur gear 42 rotated as it is keyed to the same shaft as the worm gear 38. Now, the meshing of the spur gear 42 with the larger spur gear 46 causes rotation of the large spur gear 43 and its integral centrally located sleeve nut 44. When the sleeve nut 44 is rotated there is occasioned a relative movement by the cutting tool 16 therewith. The rectangularly shaped elongated portion 56 of the tool 16 is confined in a comparably shaped rectangular passage in the side of the head 15 so there can be no rotation of the tool 16 about its own longitudinal axis. Thus when the sleeve nut 44 is rotated there is a relative rotation of the meshing threaded portions 55 and 57 to thereby cause extension or retraction of the tool 16 from or into the head 15. Normal rotation of the head 15 will cause a gradual and positive extension of the tool .16 to cut any number of multiple pipes and cement fillers as desired and necessary.

The cutter head 15 is provided with a circular ring 67 around its top which defines the opening through which drive is imparted thereto from the gear reducer 17. The ring 67 has an internal annular ilange 69. The ring is held to the head 15 by cap screws 76 at intervals there around. An annular flange '71 on the lower extension 18 of the gear reducer housing engages the internal annular groove 68 for relative rotational movement. This construction in addition to permitting separate rotation of the head 15 securely holds the head 15 against longitudinal separation of the head from its support on the gear reducer housing.

As best shown in FIGURE 4 cooperative electrical con tact brackets 72 and 75 of spring material are riveted or otherwise fastened to the stationary housing 1% at 74 and 75 respectively. Electrical lead wires 76 and 77 join the contact brackets and extend upwardly to the surface. Each of the contact brackets is provided with an electrical contact 78 and 79 which project inwardly toward each other. The lead wires 76 and 77 electrically engage the contacts 78 and 79' with suitable insulation from the spring brackets 72 and 73. A cam-like actuator 80 is fastened to the circular ring 67 by ca-p screws 81. The contacts 7 8 and 79 are normally spaced apart, but on each revolution of the head 15 the cam member 80 engages the back side of the spring contact carrier 72 to force it outwardly and thereby cause the electrical contacts 78 and 79 to complete an electrical circuit. As best shown in FIGURE 7 the circuit includes a source of at 82 and a reversible counter 83. An indicator pointer 84 cooperates with a scale 85 calibrated to either record the number of revolutions of the head 15 or to directly show just how far the cutter 16 is extended or retracted. The reversible counter 83 is of course positioned above the surface of the body of water in which the cutting device of this invention is submerged. A manually operated reversing switch is mounted on top of the counter 83 and includes a throw arm 86 and spaced contact points 87 and 88. When the motor 22 is driven in one direction the switch arm 86 is thrown to engage the contact 87 and thus cause the pointer 84 to move clockwise around its dial 85. Conversely when the arm 86 is thrown to the other contact 88 at the time when the motor 22 is re versed to cause a retraction of the cutting tool 16 the pointer turns counterclockwise and indicates to the operator when the cutting tool is fully withdrawn into the head 15.

Obviously operation of the device contemplates the initial positioning of the entire assembly within a pipe to be cut. The mechanism is lowered into a pipe by the cable 29 whereafter when it reaches the desired level the operator actuates the extensible jaws 19* and 20 which in turn cooperate with their oppositely disposed jaws 19b and 19c and 20b and 200 respectively to securely hold the cutting head in position during the cutting operation as described above.

I am aware that numerous details of construction may be varied throughout a wide range without departing from the principles disclosed herein and I therefore do not intend to limit the scope of the patent granted hereon otherwise than as necessited by the appended claims.

What is claimed is:

1. A cutter for pipe of the type cutting from inside out comprising a rotating cutting head, said rotating cutting head having a diameter substantially the same as the internal diameter of the pipe to be cut, a cutting tool disposed transversely within said cutting head and near a diameter thereof, said cutting tool having a length substantially equal to the diameter of said cutting head, means in said cutting head guiding said cutting tool for radial extension, and means for extending said cutting tool radially outwardly dun'ng rotation of said cutting tool.

2. A device as set forth in claim 1 in which the means extending said cutting tool includes a worm and worm gear drive.

3. A cutter for pipe of the type cutting from inside out comprising a cutting head having a cylindrical housing of a diameter approximately the same as the internal diameter of the innermost pipe to be cut, a cutting tool disposed transversely within said cutting head and being of a length substantially equal to the diameter of said cutting head, means radially extending said cutting tool from said cutting head, means positioning said cutting head within a pipe to be cut at any desired location, and means rotatably driving said cutting head.

4. A device as set forth in claim 3 in which the means radially extending said cutting tool includes a threading of the inner end of said cutting tool for engagement by a cooperative threaded sleeve nut.

5. A device as set forth in claim 4 in which the means radially extending said cutting tool further includes a worm, worm gear and spur gear drive to effect rotation of said threaded sleeve nut.

6. A device as set forth in claim 4 in which the means radially extending said cutting tool further includes a stationary worm, a worm gear revolving around said worm by rotation of said cutting head, and spur gears driven by said Worm gear and in turn engaging and driving said threaded sleeve nut whereby as the cutting head is rotated the cutting tool is radially extended at a rate of speed commensurate with the rate of speed of the cutting head and the pitch of the threads on the cutting tool and its cooperative threaded sleeve nut.

7. A pipe cutter of the type cutting from inside out comprising a motor, a cable for suspending said motor within a pipe, mean-s holding said motor at any desired position within the pipe to be cut, a shaft driven by said motor, a pipe cutting head joined to and driven by said shaft, a cutting tool disposed transversely within said cutting head, means extending said cutting tool from said cutting head during rotation of said cutting head, said means extending said cutting tool comprising gearing mounted intermediate a stationary portion of said motor and said cutting tool, and whereby the rotation of said cutting head causes the extension of said cutting tool through said gearing.

8. A pipe cutter of the type cutting from inside out comprising a support, means lowering said support within a pipe, driving means carried on said support, a head rotatably driven by said driving means separately from said support, and means propelling a cutter element radially outwardly from said head in response to rotation of said head in one direction and withdrawing said cutter element within said head in response to rotation of said head in an opposite direction.

9. A device as set forth in claim. 8 in which there is included remotely positioned means to indicate the amount of extension of the cutter element from the head.

10. A pipe cutter of the type cutting from inside out comprising a. support, a cutting head, means on said support for rotatably driving said head relatively to said support, means clamping said support within a pipe in any desired location therein, said means for clamping including vertically spaced apart radially outwardly movable jaws, a vertically disposed rod journally supported for Vertical sliding movement in said support, a cam element on said rod located adjacent each of said radially movable jaws, and cylinder and piston means operable by fluid under pressure for moving said rod either up or down and either causing said jaws to simultaneously extend or be permitted to retract.

References Cited in the file of this patent UNITED STATES PATENTS 764,636 Shaokelford July 12, 1904 872,290 Lusk Nov. 26, 1907 10 2,830,762 Christensen Apr. 15, 1958 2,848,165 Gerrells Aug. 19, 1958 2,904,250 Allebach Sept. 15, 1959 2,915,819 ODay et al Dec. 8, 1959 

